Active matrix organic light emitting diode (AMOLED) display is a display technique applied to a television and a mobile device, and has a broad application prospect in a power-sensitive portable electronic device due to its characteristics of lower power consumption, low cost and large size.
At present, in the AMOLED display field, in particular, in the large-size substrate design, a backplane thin film transistor (TFT) has problems of uniformity and stability in the technical process of production. On one hand, this would cause that a threshold voltage offset exists between different TFTs; on the other hand, stability of TFT is reduced after opening a bias voltage for a long time. These problems cause non-uniformity and instability of current for driving an OLED, thereby affecting the display effect.
In the prior art, there are many AMOLED compensation circuit designs performed by considering only the problem of the threshold voltage offset. However, these designs neglect the problem that the load of a gate signal line is raised gradually with the trend of the large size of AMOLED, which results in occurrence of voltage attenuation on the gate signal line, so as to affect current uniformity in the display area. These problems cause non-uniformity of light emitting of OLED, which reduces the display effect.